Kyle Wiens:

Aside from using it, there’s not much you can do with modern ag equipment. When it breaks or needs maintenance, farmers are dependent on dealers and manufacturer technicians—a hard pill to swallow for farmers, who have been maintaining their own equipment since the plow.
 “[DIY repair] is cheaper than calling out the technician. But that information is just not out there,” Dave explained to me.
 The cost and hassle of repairing modern tractors has soured a lot of farmers on computerized systems altogether. In a September issue of Farm Journal, farm auction expert Greg Peterson noted that demand for newer tractors was falling. Tellingly, the price of and demand for older tractors (without all the digital bells and whistles) has picked up. “As for the simplicity, you’ve all heard the chatter,” Machinery Pete wrote. “There’s an increasing number of farmers placing greater value on acquiring older simpler machines that don’t require a computer to fix.”
 The problem is that farmers are essentially driving around a giant black box outfitted with harvesting blades. Only manufacturers have the keys to those boxes. Different connectors are needed from brand to brand, sometimes even from model to model—just to talk to the tECU. Modifications and troubleshooting require diagnostic software that farmers can’t have. Even if a farmer managed to get the right software, calibrations to the tECU sometimes require a factory password. No password, no changes—not without the permission of the manufacturer.